Lathe dog



April 1947- R. w. BARGGREN 2,418,864

LATHE DOG Filed Deg. 4, 1944 Big Patented Apr. 15, 1947 UNITED STATES-1 LATHE nos Richard W. Barggren, Niles, 111., assignor to Dan L. Klein, Grand Rapids, Mich.

Application December 4, 1944, Serial No; 566.433

1 Claim.

The present invention relates to lathe dogs and has for its main object the provision of a lathe dog which is simple in construction and operation and which is automatic in gripping the work without the requirement of screws.

A still further object of the present invention is the provision of a lathe dog of simplified construction and which would require the minimum of parts.

With the above general objects in view and others that will appear as the invention is better understood, the same consist in the novel con struction, combination and arrangement of parts hereinafter more fully described, illustrated in the accompany drawing and pointed out in the ppended claim.

In the drawing forming a part of this application and in which like designating characters refer to corresponding parts throughout the several views:

Fig. 1 is a side elevational view of a lathe with the work in an operative position, and the lathe dog in an operative position upon the work;

Fig. 2 is an enlarged cross-sectional view through the work, showing the lathe dog and face plate in a side elevation;

Fig. 3 is a cross-sectional view through the lathe dog on line 3-3 of Fig. 2;

Fig. 4 is a cross-sectional View on line 4-4 of Fig. 3;

Fig. 5 is a cross-sectional view on line 55 of Fig. 4; and

Fig. 6 is a cross-sectional view on line 66 of Fig. 4.

Referring in detail to the present drawing there is shown a lathe generally indicated by Hi, having a driven shaft H, with face plate l2 rigidly carried by said shaft H and a work-engaging pin !3 formed centrally of said face plate l2. Said face plate 12 carries an off-centrically positioned pin hi, the latter engaging cam lever 15 of lathe dog generally indicated by IS in Fig. 1. Pin 13 as well as adjustable pin 1'! engage work 98. Dog I6 is inserted over work I8 and through the medium of pin is and cam lever l5 rotary movement to work 18 is imparted from face plate l2. This is the known use, object and purpose of a lathe dog, and to which no claim is made.

My invention resides entirely in the novel and useful construction of the lathe dog itself, which includes an annular base l9, having a transverse central bore 20 of a suitable diameter within which work It is adapted to enter, and within which the same is adapted to be clamped by means later described.

for shifting movement.

Said base I9 is further provided with a radial recess 2|, which, however, does not extend through the periphery of said base l9, but does communicate with bore 20, for seating therewithin jaw 22, and within which the latter is adapted The operative edge of said jaw 22 is arcuate as at 23 for engaging the periphery of work l8.

Passed through the periphery of said base I9, in a radial direction and substantially centrally of the inner end of said jaw 22 is screw 24 for the purpose of shifting said jaw 22 to or away from bore 26 for the purpose of adjusting said jaw depending upon the diameter of work I8. Locknut 25 upon screw 24 when in contact with the periphery of base 19 locks said screw 24 in its adjusted position, thereby maintaining jaw 22 in its rigid position with respect to work l8.

At a point diametrically opposite from recess 2! slot 26 is made in the body of base 19, which is in communication with bore 20, for seating therewithin cam 21, which is integrally formed with lever l5.

Coil spring 28 attached by one of its ends to lever l5 and adjacent the periphery of base I 9, and to screw 29 by its opposite end, tends to maintain cam 2'! in engagement with work l8.

When lever 55 is shifted against the tension of Spring 28, cam 21 is entirely brought out from the path of bore 29, thereby permitting insertion of work 18 within bore 20, preparatory to the placing of said work and of the lathe dog within the lathe.

To complete the structure of the lathe dog an annular closure plate 30 is provided with a centrol bore 3| corresponding to the diameter of bore 211 in said base is. At two diametrically opposite points in base [9 countersunk bores 32 are made to receive screws 33, which, by their threaded ends, pass through and engage plate 30, their ends being flush with the outer face of said closure plate 30. Heads of said screws 33 remain countersunk within said base [9, as is seen in Fig. 5.

Pin 3 passing through base I9 and closure plate 36, as well as cam 21 provides a pivot for the latter upon which it is adapted for rotary shifting movement on actuation of lever I 5, as is hereinabove described.

Made in closure plate 30 and in the path of one of side edges of jaw 22 is bore 35 for receiving therewithin head of screw 36, the threaded end of which engages and passes through base I9. An annular depression 31, which is in alinement with bore 35 is made upon the inner face of base l9 for the purpose of providing play for the head or said screw 3E. Head of screw 36,- engaging jaw 22, as is seen in Fig. 6, provides frictional means for maintaining said jaw 22 in position when the same is in the process of adjustment by screw 24, thereby preventing excessive and uncalled-for shifting of said jaw 22 within recess 2! when it is being adjusted by'said screw 24 When=1work l8" been placed withih bores 20 and 3|, with cam 21 engaging it by virtue of the tension exerted upon lever I5 by spring 28; said work as well as the lathe dog thereupon are both placed within pins [-3 and [1. Pin 14 caming in contact with lever 15-, and transversely thereof, and operating therea'gain'st froih theedge opposite from that at which spring 28 engages the same, tends to maintain cam '21 in its operative gripping engagement with work i8, andindependently of the action of sprin 28, assuming of course that pin l-lwith its face plate l2rrevolve into a 'counterclbckwise direction when viewed from the showing ma'i i e'Figs. 2" and 4'. When the'w'ork and the lathe dcgare-rempved from thelathe shifting of lever 15 into the opposite direction, or against the-tension'of spring 28", will shift cam 21- i'nto slot 26, out of the'patl'i" of bores 20 and 31', and out cf'its engagement witn work [8, and thereupon the lathe dbgfrhay Jae-removed without anydifificnltyfi nr work 1 8 Whilethereis described hereina preferred embodiment of the present invention; it is neverthieless to be understood that "minor changes-may be made thereih witliout departingiromthe spirit and scope of'tl'ie inventionas claimed.

What I cla-iinaasnew is:

A lathe dog comprising a casing, said casing being provided with a recess and a slot, a jaw receivable within said recess, a cam rotatably mounted in said slot, a closure plate attachable to said base for maintaining said jaw and said cam in their operative positions within said base, said base and said closure being provided with alined bores for receiving, therewithi-nthe Work to: be: clamped: therewithin by 'saidLjaW and said cam for rigidly locking the same to said base and said closure plate, means for shifting said jaw within said recess in contact with said work and for rigidly locking the same in engagement with said work, and means for frictionally engaging said jaw with said base during the shifting movement of said jaw on operation of said first named means: said last" named means including a bore made i-nsaid closure plate and partially in the path of the edge of said jaw and a screw in threaded engagement with said base, the head of the screw bei-ngjseated within said last named bore-for frictionally engaging the edge of saidj'aw'. v

RICHARD W; BARG'GREN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date v A 497,517 Ehrhardt May 16,. 189'? 1195,8118 Ingham Aug. 22; 1 91b 1,419,452 Fraser June I3; 1922' 

